Canister type vacuum cleaners, per se, are well-known and comprise a cylindrical container which frequently has a diameter substantially equal to the height thereof. The bottom of the canister is closed and the open upper end of the canister supports a closure member which actually comprises a suction unit including a suitable suction fan which draws air through an opening in the sidewall of the canister up through a filter member, and discharges the air from the upper portion of the suction unit. The suction unit is supported by the upper end of the canister by suitable latching means and when it is desired to empty the canister, it is necessary to detach the suction head from the upper end of the canister and then dump the canister.
In general, slidable, gate-type valve means are used in many types of structures, especially in valves intended to control the flow of fluids in conduits but, as far as is known, canister type vacuum cleaners have not heretofore employed any type of discharge means in the bottom of the canister, either those employing gate-type valves or otherwise.